Dissolved organic carbon uptake in streams: A review and assessment of reach‐scale measurements

Authors

Madeleine M. Mineau, University of New Hampshire, DurhamFollow
Wilfred M. Wollheim, University of New Hampshire, DurhamFollow
Ishi Buffam, University of Cincinnati
Stuart E. G. Findlay, Cary Institute of Ecosystem Studies
Robert O. Hall Jr., University of Wyoming
Erin R. Hotchkiss, Virginia Polytechnic Institute and State University
Lauren E. Koenig, University of Connecticut, Storrs
William H. McDowell, University of New Hampshire, DurhamFollow
Thomas B. Parr, University of Delaware

Abstract

Quantifying the role that freshwater ecosystems play in the global carbon cycle requires accurate measurement and scaling of dissolved organic carbon (DOC) removal in river networks. We reviewed reach‐scale measurements of DOC uptake from experimental additions of simple organic compounds or leachates to inform development of aquatic DOC models that operate at the river network, regional, or continental scale. Median DOC uptake velocity (vf) across all measurements was 2.28 mm min−1. Measurements using simple compound additions resulted in faster vf (2.94 mm min−1) than additions of leachates (1.11 mm min−1). We also reviewed published data of DOC bioavailability for ambient stream water and leaf leachate DOC from laboratory experiments. We used these data to calculate and apply a correction factor to leaf leachate uptake velocity to estimate ambient stream water DOC uptake rates at the reach scale. Using this approach, we estimated a median ambient stream DOC vf of 0.26 mm min−1. Applying these DOC vf values (0.26, 1.11, 2.28, and 2.94 mm min−1) in a river network inverse model in seven watersheds revealed that our estimated ambient DOC vf value is plausible at the network scale and 27 to 45% of DOC input was removed. Applying the median measured simple compound or leachate vf in whole river networks would require unjustifiably high terrestrial DOC inputs to match observed DOC concentrations at the basin mouth. To improve the understanding and importance of DOC uptake in fluvial systems, we recommend using a multiscale approach coupling laboratory assays, with reach‐scale measurements, and modeling.

Department

Earth Systems Research Center; New Hampshire EPSCoR

Publication Date

8-6-2016

Journal Title

Journal of Geophysical Research: Biogeosciences

Publisher

American Geophysical Union (AGU)

Digital Object Identifier (DOI)

https://dx.doi.org/10.1002/2015JG003204

Document Type

Article

Recommended Citation

Mineau, M.M., W.M. Wollheim, I.D. Buffam, S.E.G. Findlay, R.O. Hall, E. Hotchkiss, L.E. Koenig, W.H. McDowell, T.B. Parr. 2016. Dissolved organic carbon uptake in streams. JGR-Biogeoscience.

Rights

©2016. American Geophysical Union. All Rights Reserved.

Comments

This is an article published by AGU in Journal of Geophysical Research: Biogeosciences in 2016, available online: https://dx.doi.org/10.1002/2015JG003204